The present invention relates to a seat belt locking mechanism and, more particularly, to a seat belt locking mechanism having a pneumatically inflatable air bladder for activating the locking or unlocking of a seat belt.
It is often desirable, such as on amusement park type rides, to provide passengers with seat belts which can be locked, or unlocked, simultaneously by a remote operator to ensure that the seat belts are securely fastened. Pressure activated seat belt mechanisms which have been used in the past have generally relied on a piston-cylinder type arrangement. For instance, U.S. Pat. No. 3,963,090 Hollins shows an automatic seat belt buckle unlatching mechanism which has a cylinder-piston arrangement in communication with an engine intake manifold. When the engine is started, a vacuum is created in the cylinder by the engine intake manifold, which in turn causes a cam shaft extending from the cylinder to draw inwardly and disengage from the latching mechanism. Accordingly, a spring will then urge the latching mechanism upwardly to lock the seat belt. Likewise, when the engine is turned off or stalled, the absence of a vacuum in the cylinder will cause the cam shaft to be urged against the latching mechanism to release or unlock the seat belt. Although the device is suitable for combustion type engines, it does not appear suitable for vehicles or amusement park rides which may operate by electricity, or which do not necessarily require that an engine be turned off. Further, the device as shown in the Hollins patent uses a complicated piston-cylinder type mechanism. Other seat belt mechanisms generally known have used an electrical solenoid as an actuator to lock or unlock the seat belt. However, these seat belt locking mechanisms require elaborate adjustment procedures every time a seat belt unit is removed and replaced, which is fairly often in frequently used seat belts such as those on amusement park rides. Further, another disadvantage of this design is that the components are custom made and have a relatively short life span.
Accordingly, there has existed a definite need for an automatic seat belt locking mechanism for overcoming these problems. Further, there is a need for a seat belt locking mechanism which can be activated by a remote operator, or by one other than the user of the seat belt if necessary, and which is easy to manufacture, has few custom-made parts, is durable, and which does not require any adjustments or extensive maintenance. The present invention satisfies these needs and provides further related advantages.